The present invention relates to experimental and biological production technology, and more specifically to disintegrators.
The invention may be widely used for disintegrating in liquid media powers of natural and synthetic complex organic compounds such as biologically active compounds to obtain particles of less than 0.5.mu.m; as well as for disintegrating plant, animal and microbic cells in biochemical and microbiological laboratories, and in the pharmaceutical, microbiological, food and paint-making industries.
There are presently known in the art disintegrators having a milling chamber filled with milling bodies comprising balls. Prior art disintegrators differ from each other in the means for agitating milling bodies and the material being handled. In some disintegrators, vibratory, jerking, orbital and other kinds of compound motion are imparted to the milling chambers for agitating milling bodies and the material being handled, while it is also known to provide high-speed and ultra-high speed vane-type agitators or multiple disc-type agitating rotors in the milling chambers.
Known disintegrators operate either in the intermittent loading unloading manner or continuously. Continuous disintegrators are provided with pumps for feeding the material to be treated under pressure into the milling chamber. All disintegrators have cooling systems. Continuous disintegrators manufactured by WAB company (Switzerland) covered by U.S. Pat. No. 3,536,266 using spherical glass milling bodies of 0.1-1.0 mm diameter differ from the above-described disintegrators in having a large volume of milling chambers and high productivity so that they may be commercially used. WAB company manufactures a range of modularized disintegrators with milling chambers having the volume of 0.3-0.6-5.0-50-200 1.
The disintegrator comprises a cylindrical milling chamber with a height-to-diameter ratio of about 4:1 having a cooling system. Openings for feeding and discharge of the material being disintegrated are made in the cylindrical surface of the milling chamber adjacent to the end walls. A multiple disc-type agitator is concentrically mounted within the chamber and is rotated by an electric drive. Spherical glass milling bodies are placed in the milling chamber and agitated by the multiple disc-type agitator. An external delivery pump feeds a suspension of the material being disintegrated into the milling chamber, pumps it through the layer of agitated milling bodies and expells the disintegrated material through the discharge opening from the milling chamber.
It should be noted that the term "suspension" implies herein a liquid, such as water containing particles of biological, microbiological or organic material.
The main disadvantage of the prior art disintegrator consists of an intensive wear on the walls of the milling chamber, and discs of the agitator and milling bodies which is due to a high hardness (7-8 points in the Knup scale) of glass milling bodies.
An intensive wear of the above-mentioned surfaces of the disintegrator is accompanied by a number of physical, chemical and mechanical phenomena adversely affecting the structure and properties of the material being handled, namely,
(1) peptization of glass in a liquid medium used to transfer a material being disintegrated into the milling chamber; PA1 (2) abrupt raise of local pressures and temperatures at points with the impact contact of glass milling bodies; PA1 (3) formation of inclusions of ultrafine particles of glass and metal in the material being disintegrated: PA1 (4) chemical reactions between the inclusion material of ultrafine particles and the material being disintegrated; PA1 (5) change in pH of a suspension of the material being disintegrated; PA1 (6) thermomechanical degrading of the material being disintegrated in the zone with impact contact of glass milling bodies. PA1 (1) elimination of abrasion of the milling chamber and agitator surfaces, thereby preventing the material being disintegrated from being contaminated; PA1 (2) reduction of pressure, frction and heat release in the zone of impact contact of milling bodies by hundreds of times, whereby the thermomechanical and chemical degrading of the material being disintegrated is materially diminished; PA1 (3) material improvement of the efficiency of the disintegrator.
The above-mentioned phenomena result in a material reduction of biological activity of the final microbic disintegrates, thermomechanical and chemical decomposition of powders of complex organic compounds being disintegrated and in contamination of the material being treated with glass and metal particles.
A substantial diasadvantage of the conventional disintegrator also consists in an inadaquate distribution of flows of the transporting liquid in the milling chamber resulting in the formation of large-volume stagnation zones between the discs of the agitator.
Stagnation zones reduce the effective volume of the milling chamber thereby diminishing the specific productivity of the disintegrator (per unit of volume of the milling chamber).
The stagnation zones result in an increased residence time of the material being treated in the milling chamber, and hence, in overdisintegration.
It is an object of the present invention to eliminate the above disadvantages.
The main object of the invention is to provide a disintegrator which is suitable for disintegrating biological and organic products (cells of microorganisms, animals and plants, biopolymers, complex organic compounds) without substantially reducing the biological activity and without any thermomechanical destruction of the final disintegrated products.
Another object of the invention is to provide a disintegrator which permits the disintegration of powdery organic products to a particle size of less than 0.5.mu.m.
Still another object of the invention is to provide a disintegrator which disintegrates biological and organic products with their initial high purity remaining unchanged.
A further object of the invention is to provide a disintegrator having a productivity which is much greater than that of conventional apparatus of this type.
The invention consists of the provision for a disintegrator having the components so constructed as to enable uniform control of the intensity of mechanical action of the milling bodies on the material being treated over the entire volume of the milling chamber, whereby biological and organic products can be disintegrated at a high rate with their initial purity remaining at high level, while eliminating the thermomechanical destruction and any appreciable reduction of biological activity of the materials being treated.